I have uploaded a file stamp.g (and covering note stamp.doc) to
the pub/incoming directory on samson.math.rwth-aachen.de.
They contain some routines for computing with large degree
permutation groups. They should be usable up to degree 5 million or
so with care (and enough RAM). The general idea is to avoid making a
stabchain at all costs, and to avoid multiplying permutations
They don't do anything incredibly clever, and they are not very
polished, but I thought someone might have a use for them.